'When you hear hoofbeats, think of horses not zebras' - the old adage is well-known to GPs but what should you do when faced with a zebra, not a horse? Consultant cardiologist Professor Robert Tulloh and GP Dr Louise Tulloh kick off our new series with their advice on how to catch Kawasaki disease in general practice.

Doctor's duty should be to give moral lead

GPs should steer clear of prescribing antibiotics for lower respiratory tract infections even when symptoms have lasted three weeks or more, new research concludes.

The study found coughs lasted for an average of around 20 days from start to finish, without benefiting from antibiotic treatment.

The researchers said patients should be warned to prepare for a longer than expected illness ­ and advised that antibiotics would not be effective.

Their study, presented at the annual meeting of the UK Federation of Primary Care Research Organisations in Bristol, found severe cough, longer duration before visiting a GP and restriction of activities on the day of consultation all predicted longer duration (see box at end).

The research was a sub-analysis of a trial of 807 patients published in JAMA earlier this year that showed antibiotics had

no effect on the duration or severity of coughs and only marginal effect on other symptoms.

Study leader Dr Mike Moore, a GP in Salisbury, said: 'People come to the doctor because they're concerned they have already had a cough for a week and they want to know how long it's going to go on. If we do provide more information about natural history and explain they're probably going to be coughing for on average another 12 days and some even longer, and that's normal, people will feel less anxious.'

Dr Moore, senior lecturer in the department of community clinical sciences, University of Southampton, added: 'People wait about eight or nine days before they come to the doctor in the first place so giving an immediate prescription is unlikely to make them better that much quicker.'

Professor Richard Wise, chair of the Government's specialist advisory committee on antimicrobial resistance, said: 'It's important that we understand the natural history of the disease.

'There's a great spectrum of presenting signs and symptoms in lower respiratory tract infections and we need to decide which need treatment and which don't rather than handing out antibiotics willy nilly.'

The study found coughs rating as 'at least a slight problem' lasted an average of 11.7 days after consultation, with more severe coughs lasting longer.

ewilkinson@cmpinformation.com

Factors that increase length of cough

· Longer illness before consulting GP ­ 0.1 days longer for each day before appointment

· Severe cough ­ 0.66 days longer for each point on a seven-point scale

· Restriction of activities on the day of consultation ­ 0.8 days longer